OSM Ausschnitte herunterladen

<www.openstreetmap.org/export>

osm export

Das R-Paket XML - Gaston Sanchez

library("XML")

Gaston Sanchez - Dataflow

Seine Arbeit sieht man hier.

Das Arbeiten mit XML Daten

Gaston Sanchez - Webdaten bekommen

Funktionen im XML Paket

Einzelne Objekte finden

<www.openstreetmap.org/export>

osm export

Beispiel: administrative Grenzen Berlin

Administrative Grenzen für Deutschland

url <- "https://api.openstreetmap.org/api/0.6/relation/62422"

BE <- xmlParse(url)

BE <- xmlParse("../data/62422.xml")

Administrative Grenzen Berlin

Das XML analysieren

• Tobi Bosede - Working with XML Data in R

xmltop = xmlRoot(BE)
class(xmltop)

## [1] "XMLInternalElementNode" "XMLInternalNode"       
## [3] "XMLAbstractNode"

xmlSize(xmltop)

## [1] 1

xmlSize(xmltop[[1]])

## [1] 337

Nutzung von Xpath

Xpath, the XML Path Language, is a query language for selecting nodes from an XML document.

xpathApply(BE,"//tag[@k = 'population']")

## [[1]]
## <tag k="population" v="3440441"/> 
## 
## attr(,"class")
## [1] "XMLNodeSet"

Quelle für die Bevölkerungsgröße

xpathApply(BE,"//tag[@k = 'source:population']")

## [[1]]
## <tag k="source:population" v="http://www.statistik-berlin-brandenburg.de/Publikationen/Stat_Berichte/2010/SB_A1-1_A2-4_q01-10_BE.pdf 2010-10-01"/> 
## 
## attr(,"class")
## [1] "XMLNodeSet"

-Statistik Berlin Brandenburg

Etwas überraschend:

xpathApply(BE,"//tag[@k = 'name:ta']")

## [[1]]
## <tag k="name:ta" v="<U+0BAA><U+0BC6><U+0BB0><U+0BCD><U+0BB2><U+0BBF><U+0BA9><U+0BCD>"/> 
## 
## attr(,"class")
## [1] "XMLNodeSet"

Geographische Region

region <- xpathApply(BE,
  "//tag[@k = 'geographical_region']")
# regular expressions
region[[1]]

## <tag k="geographical_region" v="Barnim;Berliner Urstromtal;Teltow;Nauener Platte"/>

<tag k="geographical_region" 
  v="Barnim;Berliner Urstromtal;
  Teltow;Nauener Platte"/>

Landkreis

Barnim

Weiteres Beispiel

url2<-"http://api.openstreetmap.org/api/0.6/node/25113879"
obj2<-xmlParse(url2)
obj_amenity<-xpathApply(obj2,"//tag[@k = 'amenity']")[[1]]
obj_amenity

## <tag k="amenity" v="university"/>

Wikipedia Artikel

xpathApply(obj2,"//tag[@k = 'wikipedia']")[[1]]

## <tag k="wikipedia" v="de:Universität Mannheim"/>

xpathApply(obj2,"//tag[@k = 'wheelchair']")[[1]]

xpathApply(obj2,"//tag[@k = 'name']")[[1]]

Das C und das A

url3<-"http://api.openstreetmap.org/api/0.6/node/303550876"
obj3 <- xmlParse(url3)
xpathApply(obj3,"//tag[@k = 'opening_hours']")[[1]]

## <tag k="opening_hours" v="Mo-Sa 09:00-20:00; Su,PH off"/>

Hin und weg

url4<-"http://api.openstreetmap.org/api/0.6/node/25439439"
obj4 <- xmlParse(url4)
xpathApply(obj4,"//tag[@k = 'railway:station_category']")[[1]]

## <tag k="railway:station_category" v="2"/>

• Wikipedia Artikel Bahnhofskategorien

Exkurs: Bahnhofskategorien

• rvest: Easily Harvest (Scrape) Web Pages

library(rvest)

## Loading required package: xml2

## 
## Attaching package: 'rvest'

## The following object is masked from 'package:XML':
## 
##     xml

bhfkat<-read_html(
  "https://de.wikipedia.org/wiki/Bahnhofskategorie")
df_html_bhfkat<-html_table(
  html_nodes(bhfkat, "table")[[2]],fill = TRUE)

Bahnhofskategorien Übersicht

Nur fliegen ist schöner

url5<-"http://api.openstreetmap.org/api/0.6/way/162149882"
obj5<-xmlParse(url5)
xpathApply(obj5,"//tag[@k = 'name']")[[1]]

## <tag k="name" v="City-Airport Mannheim"/>

xpathApply(obj5,"//tag[@k = 'website']")[[1]]

## <tag k="website" v="http://www.flugplatz-mannheim.de/"/>

xpathApply(obj5,"//tag[@k = 'iata']")[[1]]

## <tag k="iata" v="MHG"/>

Das Paket osmar benutzen

library("osmar")

## Loading required package: RCurl

## Loading required package: bitops

## Loading required package: geosphere

## 
## Attaching package: 'osmar'

## The following object is masked from 'package:utils':
## 
##     find

node_ <- xmlParse("../data/162149882.xml")
node_osmar <- as_osmar(node_)
node_osmar

## osmar object
## 0 nodes, 1 ways, 0 relations

Drei Typen von Vektorobjekten

Die Ausdehnung

Import mit dem Paket sf

library(sf)

## Linking to GEOS 3.6.1, GDAL 2.2.3, proj.4 4.9.3

• Mit dem Befehl st_layers kann man sehen, welche Layer verfügbar sind:

st_layers("../data/Amsterdam_highway_primary.osm")

## Driver: OSM 
## Available layers:
##         layer_name       geometry_type features fields
## 1           points               Point       NA     10
## 2            lines         Line String       NA      9
## 3 multilinestrings   Multi Line String       NA      4
## 4    multipolygons       Multi Polygon       NA     25
## 5  other_relations Geometry Collection       NA      4

Import von Layer lines

dat <- st_read("../data/Amsterdam_highway_primary.osm","lines")

## Reading layer `lines' from data source `D:\github\geocourse\data\Amsterdam_highway_primary.osm' using driver `OSM'
## Simple feature collection with 1464 features and 9 fields
## geometry type:  LINESTRING
## dimension:      XY
## bbox:           xmin: 8.333102 ymin: 49.32801 xmax: 8.627991 ymax: 49.65208
## epsg (SRID):    4326
## proj4string:    +proj=longlat +datum=WGS84 +no_defs

plot(dat$geometry)

Import von Layer points

datp <- st_read("../data/Amsterdam_highway_primary.osm","points")

## Reading layer `points' from data source `D:\github\geocourse\data\Amsterdam_highway_primary.osm' using driver `OSM'
## Simple feature collection with 800 features and 10 fields
## geometry type:  POINT
## dimension:      XY
## bbox:           xmin: 8.33654 ymin: 49.32801 xmax: 8.626969 ymax: 49.65208
## epsg (SRID):    4326
## proj4string:    +proj=longlat +datum=WGS84 +no_defs

plot(dat$geometry,pch=20,col=rgb(0,0,1,.1))

Mit einem anderen Paket plotten

library(tmap)
qtm(dat$geometry)

st_layers("../data/ams_centraal.osm")

## Driver: OSM 
## Available layers:
##         layer_name       geometry_type features fields
## 1           points               Point       NA     10
## 2            lines         Line String       NA      9
## 3 multilinestrings   Multi Line String       NA      4
## 4    multipolygons       Multi Polygon       NA     25
## 5  other_relations Geometry Collection       NA      4

datm <- st_read("../data/ams_centraal.osm","multipolygons")

## Reading layer `multipolygons' from data source `D:\github\geocourse\data\ams_centraal.osm' using driver `OSM'
## Simple feature collection with 2796 features and 25 fields
## geometry type:  MULTIPOLYGON
## dimension:      XY
## bbox:           xmin: 4.874776 ymin: 52.36088 xmax: 4.929755 ymax: 52.39393
## epsg (SRID):    4326
## proj4string:    +proj=longlat +datum=WGS84 +no_defs

sp::plot(datm$geometry)

Mehr Beispiele, wie man mit XML Daten umgeht:

• Deborah Nolan - Extracting data from XML

• Duncan Temple Lang - A Short Introduction to the XML package for R

Noch mehr Informationen

• Web Daten manipulieren

• Tutorial zu xquery

• R und das Web (für Anfänger), Teil II: XML und R

• Gaston Sanchez - String Manipulation

• Nutzung, Vor- und Nachteile OSM

• Forschungsprojekte im Zusammenhang mit OpenStreetMap

Referenzen

citation("XML")

## 
## To cite package 'XML' in publications use:
## 
##   Duncan Temple Lang and the CRAN Team (2018). XML: Tools for
##   Parsing and Generating XML Within R and S-Plus. R package
##   version 3.98-1.11. https://CRAN.R-project.org/package=XML
## 
## A BibTeX entry for LaTeX users is
## 
##   @Manual{,
##     title = {XML: Tools for Parsing and Generating XML Within R and S-Plus},
##     author = {Duncan Temple Lang and the CRAN Team},
##     year = {2018},
##     note = {R package version 3.98-1.11},
##     url = {https://CRAN.R-project.org/package=XML},
##   }
## 
## ATTENTION: This citation information has been auto-generated from
## the package DESCRIPTION file and may need manual editing, see
## 'help("citation")'.

Das neuere Paket

citation("xml2")

## 
## To cite package 'xml2' in publications use:
## 
##   Hadley Wickham, James Hester and Jeroen Ooms (2018). xml2: Parse
##   XML. R package version 1.2.0.
##   https://CRAN.R-project.org/package=xml2
## 
## A BibTeX entry for LaTeX users is
## 
##   @Manual{,
##     title = {xml2: Parse XML},
##     author = {Hadley Wickham and James Hester and Jeroen Ooms},
##     year = {2018},
##     note = {R package version 1.2.0},
##     url = {https://CRAN.R-project.org/package=xml2},
##   }